In 1999, when the first new Star Wars movie in 16 years opened, MIT hackers turned the Great Dome into a giant replica of the robot R2D2. So it’s little surprise that the Building 26 auditorium was packed on the night in January when Darth Vader came to town.

Hayden Christensen, who played the young Vader in two Star Wars movies, was at MIT to promote his new film, Jumper, about a shy Michigan kid who discovers he has the power of teleportation. Also on hand were the film’s director, Doug Liman, and Edward Farhi and Max Tegmark, MIT physics professors recruited to discuss the plausibility of the movie’s premise.

Their verdict was somewhat discouraging. “We might not have made the film if we knew quite how impossible these guys were going to tell us teleportation was going to be,” Liman said in his opening remarks. Nonetheless, both physicists tried gamely to salvage what they could of the idea. Farhi spoke about quantum teleportation, in which one subatomic particle can be made to assume exactly the same quantum state as another, even across a large distance. Tegmark speculated about whether a sheet of neutrinos or dark matter could in principle accelerate Christensen to near light speed without killing him.

Tegmark’s PowerPoint presentation featured stills from several of ­Christensen’s previous films, and he repeatedly addressed ­Christensen directly as “Hayden.” But Farhi seemed to have only the vaguest idea of who the guest of honor was. Though he spoke energetically about quantum teleportation for more than three hours–at a pre-event press conference, in small sessions with reporters afterward, and during the event itself–Farhi referred to Christensen only as “our actor” and “the distinguished actor.”

Christensen, for his part, seemed content to smile and look pretty. But Liman displayed a wit that belied his dazed expression. He explained that he had tried to be as accurate as possible in depicting the physical effects of dematerialization–the rush of air into a suddenly vacated space, the resulting condensation. But when his remarks failed to elicit any appreciable response from the otherwise rowdy audience, he surveyed the packed auditorium and said, “Other places I sound very scientific when I say that.”